Electromagnetic interference shield within integrated circuit encapsulation using photonic bandgap structure

Abstract

An encapsulated integrated circuit is provided that includes an integrated circuit (IC) die. An encapsulation material encapsulates the IC die. An electromagnetic interference (EMI) shield is provided by a photonic bandgap (PBG) structure that is included within the encapsulation material. The PBG structure is configured to have a photonic bandgap with a frequency range approximately equal to a range of frequencies that may cause EMI.

What is claimed is: 
     
       1. A device comprising:
 an integrated circuit (IC) die; 
 an encapsulation material encapsulating the IC die; 
 a photonic bandgap (PBG) structure within the encapsulation material, the PBG structure configured to have a photonic bandgap frequency range approximately equal to a range of electromagnetic interference (EMI) frequencies, the PBG structure forming an EMI shield around at least a portion of the IC die; and 
 a radio frequency (RF) circuit fabricated on the IC die, the RF circuit configured to produce a first frequency within the photonic bandgap frequency range. 
 
     
     
       2. The device of  claim 1 , wherein the PBG structure includes a matrix of periodically spaced nodes within the encapsulation material, the encapsulation material has a first permittivity, and the nodes have a second permittivity that is different from the first permittivity. 
     
     
       3. The device of  claim 2 , wherein the second permittivity is greater than the first permittivity. 
     
     
       4. The device of  claim 1 , wherein the PBG structure includes a diffusion of particles within the encapsulation material, the encapsulation material has a first permittivity, and the particles have a second permittivity that is different from the first permittivity. 
     
     
       5. A device comprising:
 an integrated circuit (IC) die; 
 an encapsulation material encapsulating the IC die; 
 a photonic bandgap (PBG) structure within the encapsulation material, the PBG structure configured to have a photonic bandgap frequency range approximately equal to a range of electromagnetic interference (EMI) frequencies, the PBG structure forming an EMI shield around at least a portion of the IC die; and 
 a circuit fabricated on the IC die, the circuit having an operation susceptible to an electromagnetic interference (EMI) frequency within the photonic bandgap frequency range. 
 
     
     
       6. The device of  claim 5 , further comprising:
 a radio frequency (RF) circuit fabricated on the IC die, the RF circuit configured to transmit or receive at a transmission frequency; and 
 an antenna structure coupled to the RF circuit. 
 
     
     
       7. The device of  claim 5 , wherein the PBG structure includes a matrix of periodically spaced nodes within the encapsulation material, the encapsulation material has a first permittivity, and the nodes have a second permittivity that is different from the first permittivity. 
     
     
       8. The device of  claim 7 , wherein the second permittivity is greater than the first permittivity. 
     
     
       9. The device of  claim 5 , wherein the PBG structure includes a diffusion of particles within the encapsulation material, the encapsulation material has a first permittivity, and the particles have a second permittivity that is different from the first permittivity. 
     
     
       10. A device comprising:
 an integrated circuit (IC) die; 
 an encapsulation material encapsulating the IC die; 
 a photonic bandgap (PBG) structure within the encapsulation material, the PBG structure configured to have a photonic bandgap frequency range approximately equal to a range of electromagnetic interference (EMI) frequencies, the PBG structure forming an EMI shield around at least a portion of the IC die; 
 a radio frequency (RF) circuit fabricated on the IC die, the RF circuit configured to transmit or receive at a transmission frequency outside the photonic bandgap frequency range; and 
 an antenna structure adjacent the IC die, the antenna structure coupled to the RF circuit. 
 
     
     
       11. The device of  claim 10 , wherein the PBG structure includes a matrix of periodically spaced nodes within the encapsulation material, the encapsulation material has a first permittivity, and the nodes have a second permittivity that is different from the first permittivity. 
     
     
       12. The device of  claim 11 , wherein the second permittivity is greater than the first permittivity. 
     
     
       13. The device of  claim 10 , wherein the PBG structure includes a diffusion of particles within the encapsulation material, the encapsulation material has a first permittivity, and the particles have a second permittivity that is different from the first permittivity. 
     
     
       14. A device comprising:
 an integrated circuit (IC) die; 
 an encapsulation material encapsulating the IC die, the encapsulation material including a first portion having a first permittivity (er 1 ) and a second portion having a second permittivity (er 2 ), the first portion surrounded by the second portion to form a dielectric resonator antenna; 
 a photonic bandgap (PBG) structure within the encapsulation material, the PBG structure configured to have a photonic bandgap frequency range approximately equal to a range of electromagnetic interference (EMI) frequencies, the PBG structure forming an EMI shield around at least a portion of the IC die; and 
 a radio frequency (RF) circuit fabricated on the IC die, the RF circuit coupled to the dielectric resonator antenna, and the RF circuit configured to transmit or receive at a transmission frequency. 
 
     
     
       15. The device of  claim 14 , wherein the PBG structure is formed within the second portion. 
     
     
       16. The device of  claim 14 , wherein the PBG structure includes a matrix of periodically spaced nodes within the encapsulation material, the encapsulation material has a first permittivity, and the nodes have a second permittivity that is different from the first permittivity. 
     
     
       17. The device of  claim 16 , wherein the second permittivity is greater than the first permittivity. 
     
     
       18. The device of  claim 14 , wherein the PBG structure includes a diffusion of particles within the encapsulation material, the encapsulation material has a first permittivity, and the particles have a second permittivity that is different from the first permittivity. 
     
     
       19. A device comprising:
 an integrated circuit (IC) die; 
 an encapsulation material encapsulating the IC die; 
 a photonic bandgap (PBG) structure within the encapsulation material, the PBG structure configured to have a photonic bandgap frequency range approximately equal to a range of electromagnetic interference (EMI) frequencies, the PBG structure forming an EMI shield around at least a portion of the IC die; and 
 a leadframe with a die attach pad, in which a portion of the PBG structure is located between the IC die and the die attach pad. 
 
     
     
       20. The device of  claim 19 , wherein the PBG structure includes a matrix of periodically spaced nodes within the encapsulation material, the encapsulation material has a first permittivity, and the nodes have a second permittivity that is different from the first permittivity. 
     
     
       21. The device of  claim 20 , wherein the second permittivity is greater than the first permittivity. 
     
     
       22. The device of  claim 19 , wherein the PBG structure includes a diffusion of particles within the encapsulation material, the encapsulation material has a first permittivity, and the particles have a second permittivity that is different from the first permittivity. 
     
     
       23. A device comprising:
 an integrated circuit (IC) die; 
 an encapsulation material encapsulating the IC die; 
 a photonic bandgap (PBG) structure including a diffusion of particles within the encapsulation material, the PBG structure configured to have a photonic bandgap frequency range approximately equal to a range of electromagnetic interference (EMI) frequencies, the PBG structure forming an EMI shield around at least a portion of the IC die, the encapsulation material having a first permittivity, and the particles having a second permittivity that is different from the first permittivity; and 
 a die attach pad on which the IC die is mounted; 
 the PBG structure including a layer between the IC die and the die attach pad.